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Does space debris cleanup include the hundreds of old Centaur rockets in disposal orbits just beyond Geosynchronous Orbit? They could be repaired and used. They all have simlar ACES like H2 - LOX engines which could be used for spare parts for repairing the better ones. The result is free rocket engines already in space, another savings. 198.203.213.110 (talk) 21:25, 18 May 2015 (UTC)[reply]

The following paragraph appears in the section, Advanced Common Evolved Stage.

"In-space propellant transfer has been used on all Soviet space stations since Salyut-6 in 1978 and is used on the ISS today. US refueling efforts were demonstrated in the 2007 Orbital Express Mission and in the 2011-2013 Robotic Refueling Mission, which raised the Technology Readiness Level (TRL) of on-orbit refueling."

This paragraph is totally irrelevant to the subject at hand. I am going to delete it. 7802mark (talk) 16:32, 21 September 2015 (UTC)[reply]

I believe the current ACES is a combination of the original ACES by Boeing and ICES by Lockheed Martin, and that while it uses the name ACES, it's based more on ICES than on the original ACES. This link may be useful, if we don't have it already: http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/EvolvedAtlasToMeetSpaceTransportationNeeds20056815.pdf Martijn Meijering (talk) 19:50, 2 January 2016 (UTC)[reply]

Short Twitter exchange with Dr Sowers, VP Advanced Concepts & Technologies at ULA: https://twitter.com/mmeijeri/status/683375844438458369 stating ACES today is very similar to the original ACES, though incorporating ICES technology. Not quite what we call a WP:RS, but a step in the right direction. Might be good to change the text to reflect this, looks as if my edit overemphasised the role of ICES. Martijn Meijering (talk) 22:37, 4 January 2016 (UTC)[reply]

Yeah Martijn Meijering, I don't know the answer, but I think you have identified an important item for further work on the article, as we get better and more complete sources to support the heritage on this. One way the current article prose can be read (interpreted) is that—back when there were two different/separated companies bidding for the US military space market (Boeing and Lockheed Martin), prior to 2006 or so—Boeing and Lockheed each did certain things:

• Boeing came up with the name ACES for some particular instantiation of a new cryogenic stage. The article, and the sources, are a bit weak on exactly what the characteristics of that ACES-named second stage.
• Lockheed Martin had a second stage concept called ICES. Based on the sources in the article, it appears as if the LockMart ICES may have been the concept that had many (although not all) of the most unique and beneficial aspects of the current (2016) ACES design that is being touted, and is well summarized by the video I just added to the external links.

When the two companies merged their launch vehicle manufacturing, and launch vehicle operations, into a single new company in 2006 (United Launch Alliance), the new company, quite naturally, kept the conceptual second stage project going, but did so as only one project rather than two, and modified the old/existing ACES/Boeing and ICES/LockMart concepts into a single one, choosing to keep the acronym of one of them (ACES), but redefining the acronym to Advanced Common Evolved Stage (had been "Advanced Cryogenic ..." while the acronym was exclusive to Boeing.

• ULA naturally put in concepts from both companies (e.g., 5 m diameter from DCSS heritage) but many (most???) of the newish and more radical concepts (IVF so no helium for pressurization, ICE auxilliary power unit, etc. from LockMark ICES concept heritage). Getting sources for exactly which aspects of the current/2016 ACES design came from the Boeing/ACES or the LockMart/ICES concepts is, to me, the goal we ought to have for improving this aspect of the article.

Not sure I have all elements of this fully understood, but that is how it is appearing based on the info we have today. Cheers. N2e (talk) 13:42, 6 March 2016 (UTC)[reply]

Hello fellow Wikipedians,

I have just modified one external link on Advanced Cryogenic Evolved Stage. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

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Thanks IAB, but I updated the link to the United Launch Alliance official site,; we don't need an archive link for this one. -- ToE 16:14, 13 February 2018 (UTC)[reply]

Hello fellow Wikipedians,

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Thanks IAB. The original link for the first one (on aiaa.org) seems to be working fine now. The second one (on ulalaunch.com) was just shuffled to a new directory, so I updated the url. For both I kept the archiveurl but set deadurl=no. -- ToE 16:07, 13 February 2018 (UTC)[reply]

There is (likely verifiable) info here from Tory Bruno (ULA CEO) on the current (not very active, and development not advancing very fast) state of ACES. [1]. It's not a full-blown super good secondary source quality source, so maybe not able to be used in the article prose yet. But it is quite useful to have this perspective on why ACES seems to always be seven years away, even nine years after the idea first surfaced. The video seems to be here: CU Engineering, at 36:47.

Bruno re ACES: "no customers"; ... "no PDR"; "no requirements".

Is really looking like there is simply no demand for ACES. N2e (talk) 05:00, 24 June 2018 (UTC)[reply]

@N2e: Per SpaceNews ACES (as you probably know) is no longer being pursued by ULA. I don't know a lot about this concept but is it time to move this article into past tense? update this article (other then mentioning it in one sentence)? OkayKenji ^{(talk • contribs)} 05:30, 2 March 2021 (UTC)[reply]

Yeah, I haven't followed the ACES news very closely lately, but I've never seen any interest by ULA as a private company to utilize private capital to develop this "product" in the ordinary way companies build new products to bring to market in hopes of making a profit over the long term. Rather, it has seemed nothing more than just yet another of the "space industrial complex" projects where the "commmercial" company would be happy to "build" something on a cost-plus contract basis if they can get the government agency to pay for it.

So, if we have no sources indicating it is currently a live program, then sure, past tense on many former present tense verbs would be a part of a good copyedit. I'll try to take a look through it in the next few days if I can find the time. Cheers. N2e (talk) 04:50, 3 March 2021 (UTC)[reply]

OkayKenji, I have given a reasonably thorough copyedit to the article to get the context straight given that this is, now, an historical concept that was never full-on built nor flight tested. It did however obtain US gvmt funding for some of the R&D and terrestrial lab testing of subsystems, although never got built for actual flight testing of such a stage. Please take a good read through the article now and see if it reads okay; fix whatever you find. Cheers. N2e (talk) 22:11, 4 March 2021 (UTC)[reply]

Recently, in a ULA infographic posted by Tory Bruno, ACES was listed as a variant of Centaur V, but this time as the "Advanced Centaur Endurance Stage." Is this relevant information pertaining to this page? Should we add this new information, and claim that ACES is no longer cancelled due to its similar functionality and same acronym? 129,743rd user (talk) 05:11, 2 September 2025 (UTC)[reply]

Sorry, forgot to add source:

https://x.com/torybruno/status/1961123896847147380 129,743rd user (talk) 05:11, 2 September 2025 (UTC)[reply]

From the episode of Tory's podcast that the X post you linked is in reference to (https://www.youtube.com/watch?v=A2eI5ex1BCA&t=1s at 12:43): Tory and Amanda Bacchetti discuss the return of ACES. They frame it as a "derivation of the current Centaur V" stage with extra "bells and whistles". Definitely worth mentioning here. Maybe making the claim that it is no longer cancelled is not exactly correct? more that engineering from the ACES project was rolled into the Centaur V family... with the same ACES acronym. This framing is more in line with some previous statements by ULA leadership:

"Peller described ACES as a concept that ULA is no longer actively pursuing. “We did a lot of studies, we invested in a lot of technology development to assess the feasibility of some of the innovative features of ACES,” he said. “That has served us well, because a lot of that original ACES work has its fingerprints in our new version of Centaur, the Centaur 5 we’re fielding with Vulcan.”" - from spacenews.com, 2020

also see this 2024 Ars Technica article where Tory Bruno is quoted about related tests on Vulcan's second flight and teases upgrades to Centaur that sound a lot like the original ACES. https://arstechnica.com/space/2024/10/ulas-second-vulcan-launch-will-pave-the-way-for-military-certification/.

I think you're right that this is relevant info to add to this article. Not sure the best way to expand from the current content though. Probably need to add a new section for Advanced Centaur Endurance Stage below the previous two names that ACES referred to. In that case the whole article might need to be renamed? Alternatively, edit the Centaur V section to include info about this if this doesn't warrant a new section. Cameronjmc (talk) 08:52, 7 December 2025 (UTC)[reply]